Description: (Taken directly from the application) The Metabolic Studies Core Laboratory will provide access to established and state-of-the-art methods for studying energy metabolism and nutrient partitioning at the whole body level in humans and animals. Consolidations of these methods in a single core laboratory is essential because of (a) the cost of the equipment and (b) the need to integrate the measures of body composition, energy expenditure, and nutrient partitioning and (c) to provide concentrated expertise to assist in study design and interpretation. Through this core laboratory, ONRC investigators will receive advice and assistance from established investigators in the application of the techniques for studying energy metabolism and nutrient partitioning to relevant experimental questions. The services chosen for inclusion in this core were primarily those deemed to be relevant to the needs of Minnesota Obesity Center investigators and the theme of prevention of obesity. This core is also visualized as the potential link between epidemiology based studies and more basic investigation. It is hoped that the presence of this core will assist in the vertical integration of obesity research within the Minnesota Obesity Center.